Hip and core exercise programme prevents running-related overuse injuries in adult novice recreational runners: a three-arm randomised controlled trial (Run RCT).

OBJECTIVE: This study aims to investigate the efficacy of two exercise interventions in reducing lower extremity (LE) injuries in novice recreational runners. METHODS: Novice runners (245 female, 80 male) were randomised into hip and core (n=108), ankle and foot (n=111) or control (n=106) groups. Interventions were completed before running and included exercise programmes focusing on either (1) hip and core or (2) ankle and foot muscles. The control group performed static stretching exercises. All groups were supervised by a physiotherapist and performed the same running programme. Injuries and running exposure were registered using weekly questionnaires during the 24-week study. Primary outcome was running-related LE injury. RESULTS: The incidence of LE injuries was lower in the hip and core group compared with the control group (HR 0.66; 95% CI 0.45 to 0.97). The average weekly prevalence of overuse injuries was 39% lower (prevalence rate ratio, PRR 0.61, 95% CI 0.39 to 0.96), and the prevalence of substantial overuse injuries was 52% lower (PRR 0.48, 95% CI 0.27 to 0.90) in the hip and core group compared with the control group. No significant difference was observed between the ankle and foot group and control group in the prevalence of overuse injuries. A higher incidence of acute injuries was observed in the ankle and foot group compared with the control group (HR 3.60, 95% CI 1.20 to 10.86). CONCLUSION: A physiotherapist-guided hip and core-focused exercise programme was effective in preventing LE injuries in novice recreational runners. The ankle and foot programme did not reduce LE injuries and did not protect against acute LE injuries when compared with static stretching.

Best practices for the dissemination and implementation of neuromuscular training injury prevention warm-ups in youth team sport: a systematic review.

OBJECTIVE: To evaluate best practices for neuromuscular training (NMT) injury prevention warm-up programme dissemination and implementation (D&I) in youth team sports, including characteristics, contextual predictors and D&I strategy effectiveness. DESIGN: Systematic review. DATA SOURCES: Seven databases were searched. ELIGIBILITY: The literature search followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. INCLUSION CRITERIA: participation in a team sport, ≥70% youth participants (<19 years), D&I outcomes with/without NMT-related D&I strategies. The risk of bias was assessed using the Downs & Black checklist. RESULTS: Of 8334 identified papers, 68 were included. Sport participants included boys, girls and coaches. Top sports were soccer, basketball and rugby. Study designs included randomised controlled trials (RCTs) (29.4%), cross-sectional (23.5%) and quasi-experimental studies (13.2%). The median Downs & Black score was 14/33. Injury prevention effectiveness (vs efficacy) was rarely (8.3%) prioritised across the RCTs evaluating NMT programmes. Two RCTs (2.9%) used Type 2/3 hybrid approaches to investigate D&I strategies. 19 studies (31.6%) used D&I frameworks/models. Top barriers were time restrictions, lack of buy-in/support and limited benefit awareness. Top facilitators were comprehensive workshops and resource accessibility. Common D&I strategies included Workshops with supplementary Resources (WR; n=24) and Workshops with Resources plus in-season Personnel support (WRP; n=14). WR (70%) and WRP (64%) were similar in potential D&I effect. WR and WRP had similar injury reduction (36-72%) with higher adherence showing greater effectiveness. CONCLUSIONS: Workshops including supplementary resources supported the success of NMT programme implementation, however, few studies examined effectiveness. High-quality D&I studies are needed to optimise the translation of NMT programmes into routine practice in youth sport.

Shoulder Check: Investigating Shoulder Injury Rates, Types, Severity, Mechanisms, and Risk Factors in Canadian Youth Ice Hockey.

OBJECTIVE: To describe shoulder-related injury rates (IRs), types, severity, mechanisms, and risk factors in youth ice hockey players during games and practices. DESIGN: Secondary analysis of data from a 5-year prospective cohort study, Safe-to-Play (2013-2018). SETTING: Canadian youth ice hockey. PARTICIPANTS: Overall, 6584 player-seasons (representing 4417 individual players) participated. During this period, 118 shoulder-related games and 12 practice injuries were reported. ASSESSMENT OF RISK FACTORS: An exploratory multivariable mixed-effects Poisson regression model examined the risk factors of body checking policy, weight, biological sex, history of injury in the past 12 months, and level of play. MAIN OUTCOME MEASURES: Injury surveillance data were collected from 2013 to 2018. Injury rates with 95% confidence interval (CI) were estimated using Poisson regression. RESULTS: The shoulder IR was 0.35 injuries/1000 game-hours (95% CI, 0.24-0.49). Two-thirds of game injuries (n = 80, 70%) resulted in >8 days of time-loss, and more than one-third (n = 44, 39%) resulted in >28 days of time-loss. An 83% lower rate of shoulder injury was associated with policy prohibiting body checking compared with leagues allowing body checking (incidence rate ratio [IRR], 0.17; 95% CI, 0.09-0.33). A higher shoulder IR was observed for those who reported any injury in the last 12-months compared with those with no history (IRR, 2.00; 95% CI, 1.33-3.01). CONCLUSIONS: Most shoulder injuries resulted in more than 1 week of time-loss. Risk factors for shoulder injury included participation in a body-checking league and recent history of injury. Further study of prevention strategies specific to the shoulder may merit further consideration in ice hockey.

A Biopsychosocial Model for Understanding Training Load, Fatigue, and Musculoskeletal Sport Injury in University Athletes: A Scoping Review.

ABSTRACT: McClean, ZJ, Pasanen, K, Lun, V, Charest, J, Herzog, W, Werthner, P, Black, A, Vleuten, RV, Lacoste, E, and Jordan, MJ. A biopsychosocial model for understanding training load, fatigue, and musculoskeletal sport injury in university athletes: A scoping review. J Strength Cond Res 38(6): 1177-1188, 2024-The impact of musculoskeletal (MSK) injury on athlete health and performance has been studied extensively in youth sport and elite sport. Current research examining the relationship between training load, injury, and fatigue in university athletes is sparse. Furthermore, a range of contextual factors that influence the training load-fatigue-injury relationship exist, necessitating an integrative biopsychosocial model to address primary and secondary injury prevention research. The objectives of this review were (a) to review the scientific literature examining the relationship between training load, fatigue, and MSK injury in university athletes and (b) to use this review in conjunction with a transdisciplinary research team to identify biopsychosocial factors that influence MSK injury and develop an updated, holistic biopsychosocial model to inform injury prevention research and practice in university sport. Ten articles were identified for inclusion in this review. Key findings were an absence of injury surveillance methodology and contextual factors that can influence the training load-fatigue-MSK injury relationship. We highlight the inclusion of academic load, social load, and mental health load as key variables contributing to a multifactorial, gendered environmental, scientific inquiry on sport injury and reinjury in university sport. An integrative biopsychosocial model for MSK injury in university sport is presented that can be used to study the biological, psychological, and social factors that modulate injury and reinjury risk in university athletes. Finally, we provide an example of how causal inference can be used to maximize the utility of longitudinally collected observational data that is characteristic of sport performance research in university sport.

Are we levelling the playing field? A qualitative case study of the awareness, uptake and relevance of the IOC consensus statements in two countries.

OBJECTIVES: Research evidence is commonly compiled into expert-informed consensus guidelines intended to consolidate and distribute sports medicine knowledge. Between 2003 and 2018, 27 International Olympic Committee (IOC) consensus statements were produced. This study explored the policy and practice impact of the IOC Statements on athlete health and medical team management in two economically and contextually diverse countries. METHODS: A qualitative case study design was adopted. Fourteen face-to-face interviews were conducted with purposively selected interviewees, seven participants from Australia (higher economic equality) and seven from South Africa (lower economic equality), representing their national medical commissions (doctors and physiotherapists of Olympic, Paralympic and Youth teams). A framework method was used to analyse interview transcripts and identify key themes. RESULTS: Differences across resource settings were found, particularly in the perceived usefulness of the IOC Statements and their accessibility. Both settings were unsure about the purpose of the IOC Statements and their intended audience. However, both valued the existence of evidence-informed guidelines. In the Australian setting, there was less reliance on the resources developed by the IOC, preferring to use locally contextualised documents that are readily available. CONCLUSION: The IOC Statements are valuable evidence-informed resources that support translation of knowledge into clinical sports medicine practice. However, to be fully effective, they must be perceived as useful and relevant and should reach their target audiences with ready access. This study showed different contexts require different resources, levels of support and dissemination approaches. Future development and dissemination of IOC Statements should consider the perspectives and the diversity of contexts they are intended for.

Players with high physical fitness are at greater risk of injury in youth football.

The aim of this study was to investigate physical fitness, football-specific skills, and their association with injury risk in youth football. Altogether 447 male and female players aged 9-14 years (median 12 years) participated in performance tests and prospective follow-up. The physical fitness tests included five-jump test for distance, 30-m sprint, football-specific figure of eight agility, countermovement jump, and Yo-Yo intermittent endurance test level 1. The football-specific skill tests included dribbling and passing tests. Injuries and exposure were registered during the 20-week follow-up. Our candidate risk factors were low/high level of physical fitness measured with a composite score of physical fitness tests and low/high level of football-specific skills measured with a composite score of dribbling and passing tests. Secondarily, we investigated performance in individual tests and their association with injury risk. During the follow-up, players reported 565 injuries (264 acute and 301 overuse injuries). High level of physical fitness was associated with increased rate of all injuries (age-, sex-, and mean team exposure-adjusted IRR: 1.28, 95% CI: 1.04-1.58). The level of football-specific skills had no influence on the overall injury rate. Burden of overuse injuries, but not acute injuries was significantly higher in most fit players compared with the players in the reference group (IRR: 2.09, 95% CI: 1.04-4.24). In conclusion, most fit players were at greater risk of sustaining injuries in youth competitive football.

Injuries and Concussions in Female High School Rugby: Prevention is Worth a Try.

OBJECTIVES: To describe injury and concussion rates and mechanisms in female high school rugby players. DESIGN: Two-year prospective cohort study. SETTING: High school rugby. PARTICIPANTS: Participants included 214 female High school rugby players (year 1) and 207 female High school players (year 2) from the Calgary Senior High School Athletics Association 2018 and 2019 rugby competition. INTERVENTION: None. MAIN OUTCOME MEASURES: Match and training injury and concussion. Injury definition included any injury resulting in time loss, inability to complete a session, and/or requiring medical attention. Details of reported injuries were collected on injury report forms and validated by a certified athletic therapist on a validated online injury surveillance platform. Exposure hours for players were tracked using paper or virtual weekly exposure forms by team designates. RESULTS: A match incidence rate (IR) = 93.7 injuries/1000 match hours (95% confidence intervals (CI): 78.6-11.7) and training IR = 5.3 injuries/1000 training hours (95% CI: 4.0-6.9) were estimated. The tackle accounted for 109 (70%) match and 37 (44%) training injuries. Tackling was the most frequent mechanism of injury (IR = 37.5 injuries/1000 match hours, 95% CI: 27.5-51.8 and 1.2 injuries/1000 training hours, 95% CI: 0.7-2.4). Sixty-two match concussions (IR = 37.5 concussions/1000 match hours, 95% CI: 26.8-52.3) and 16 training concussions (IR = 1.0 concussions/1000 training hours, 95% CI: 0.7-1.4) occurred. Of 78 reported concussions, 78% for match and 56% for training were physician diagnosed. Tackling was the most frequent mechanism of concussion in matches (IR = 18.1 concussions/1000 match hours, 95% CI:11.4-28.6). CONCLUSIONS: Injury and concussion rates in female high school rugby are high. The tackle accounted for the highest proportion of injuries. Prevention strategies (eg, tackle policy change, tackle-training programs, and neuromuscular training) should be explored to increase sport safety.

New Machine Learning Approach for Detection of Injury Risk Factors in Young Team Sport Athletes.

The purpose of this article is to present how predictive machine learning methods can be utilized for detecting sport injury risk factors in a data-driven manner. The approach can be used for finding new hypotheses for risk factors and confirming the predictive power of previously recognized ones. We used three-dimensional motion analysis and physical data from 314 young basketball and floorball players (48.4% males, 15.72±1.79 yr, 173.34±9.14 cm, 64.65±10.4 kg). Both linear (L1-regularized logistic regression) and non-linear methods (random forest) were used to predict moderate and severe knee and ankle injuries (N=57) during three-year follow-up. Results were confirmed with permutation tests and predictive risk factors detected with Wilcoxon signed-rank-test (p<0.01). Random forest suggested twelve consistent injury predictors and logistic regression twenty. Ten of these were suggested in both models; sex, body mass index, hamstring flexibility, knee joint laxity, medial knee displacement, height, ankle plantar flexion at initial contact, leg press one-repetition max, and knee valgus at initial contact. Cross-validated areas under receiver operating characteristic curve were 0.65 (logistic regression) and 0.63 (random forest). The results highlight the difficulty of predicting future injuries, but also show that even with models having relatively low predictive power, certain predictive injury risk factors can be consistently detected.

Altered hip control during a standing knee-lift test is associated with increased risk of knee injuries.

A few prospective studies have investigated hip and pelvic control as a risk factor for lower extremity (LE) injuries. The purpose of this study was to investigate whether deficits in hip and lumbopelvic control during standing knee-lift test are associated with increased risk of acute knee and LE injuries in youth team sports. At baseline, 258 basketball and floorball players (aged 12-21 years) participated in a standing knee-lift test using 3-dimensional motion analysis. Two trials per leg were recorded from each participant. Peak sagittal plane pelvic tilt and frontal plane pelvic drop/hike were measured. Both continuous and categorical variables were analyzed. New non-contact LE injuries, and match and training exposure, were recorded for 12 months. Seventy acute LE injuries were registered. Of these, 17 were knee injuries (eight ACL ruptures) and 35 ankle injuries. Risk factor analyses showed that increased contralateral pelvic hike was significantly associated with knee injury risk when using categorical variable (HR for high vs low group 4.07; 95% CI 1.32-12.6). Furthermore, significant association was found between high lateral pelvic hike angles and ACL injury risk in female players (HR for high vs low group 9.10; 95% CI 1.10-75.2). Poor combined sensitivity and specificity of the test was observed. In conclusion, increased contralateral pelvic hike is associated with non-contact knee injury risk among young team sport players and non-contact ACL injuries among female players. More research to determine the role of pelvic control as a risk factor for knee injuries is needed.

Epidemiology of all-complaint injuries in youth basketball.

This study evaluated the incidence and characteristics of all-complaint injuries, including acute and overuse injuries, in female and male youth basketball players. A total of 518 players (16 ± 1.4 years; 38.6% females), from 63 teams, participated in this prospective cohort study. Players were observed through one competitive high school or club basketball season to record exposure and all-complaint injuries, defined as any complaint resulting from participating in basketball-related activities, including but irrespective of the need for medical attention or time loss. Injury incidence rates and rate ratios were derived from Poisson's regression with 99.4% CI (Bonferroni's correction for multiple comparisons). The overall injury incidence rate was 14.4 (99.4% CI: 12.2-17.0) injuries/1000 h; 13.8 (99.4% CI: 11.2-16.8) in females and 14.8 (99.4% CI: 11.7-18.8) in males. While the incidence of injury was similar across injury classifications for female and male players, a potential lower overuse knee injury rate was noted for females vs males [IRR = 0.61 (99.4% CI: 0.34-1.07)]. The most commonly injured body location was the ankle (45%) in females and the knee (51%) in males. Overuse (vs acute) injuries were about 2x more common in the knee while acute (vs overuse) injuries were about 3x more common in the ankle, overall, and for female and male players. Based on an all-complaint injury definition, injury rates in competitive female and male youth basketball players are much higher than previously reported. This study provides an evidence base to inform more tailored interventions to reduce injuries in youth basketball.

Improved reporting of overuse injuries and health problems in sport: an update of the Oslo Sport Trauma Research Center questionnaires.

In 2013, the Oslo Sports Trauma Research Center Overuse Injury Questionnaire (OSTRC-O) was developed to record the magnitude, symptoms and consequences of overuse injuries in sport. Shortly afterwards, a modified version of the OSTRC-O was developed to capture all types of injuries and illnesses-The Oslo Sports Trauma Research Center Questionnaire on Health Problems (OSTRC-H). Since then, users from a range of research and clinical environments have identified areas in which these questionnaires may be improved. Therefore, the structure and content of the questionnaires was reviewed by an international panel consisting of the original developers, other user groups and experts in sports epidemiology and applied statistical methodology. Following a review panel meeting in October 2017, several changes were made to the questionnaires, including minor wording alterations, changes to the content of one question and the addition of questionnaire logic. In this paper, we present the updated versions of the questionnaires (OSTRC-O2 and OSTRC-H2), assess the likely impact of the updates on future data collection and discuss practical issues related to application of the questionnaires. We believe this update will improve respondent adherence and improve the quality of collected data.

Females Sustain more Ankle Injuries than Males in Youth Football.

This prospective study evaluated the incidence and pattern of acute injuries in youth (9- to 14-year- old) football players. Ten football clubs [n=730 players (567 males, 163 females)] participated in the 20-week follow-up study (January-June 2015). Data was collected by sending a standardized weekly SMS to players' parents/guardians with follow-up interviews for injured players. During the study period, 278 players (38%) sustained 410 acute injuries. The overall injury incidence for males and females was 6.47 (95% CI, 5.84-7.09) injuries per 1000 h of football exposure. Most injuries (40%) caused minimal absence from sports. Eighty-four percent of the injuries affected the lower extremities, with the ankle (30%), knee (17%), and thigh (16%) being the most commonly injured body sites. Females had significantly higher ankle injury rate (IRR) 1.85 (95% CI, 1.18-2.91, p=0.007) and non-contact ankle injury rate IRR 2.78 (95% CI, 1.91-4.02, p<0.001) than males. In conclusion, our results showed that the acute injury incidence among youth football is moderately high, and females are at higher risk for ankle injuries. Injury prevention programs aimed at preventing ankle injuries should be considered in the future.

How much, how often, how well? Adherence to a neuromuscular training warm-up injury prevention program in youth basketball.

Adherence is a key implementation outcome that determines the effectiveness of an intervention. This study, an observational design involving coaches and players from 33 high school basketball teams, evaluated the dimensions of adherence to a basketball-specific neuromuscular training (NMT) warm-up program in youth basketball. Coach adherence (daily report of team adherence) was collected prospectively. Adherence measures: cumulative utilization (proportion of total sessions possible), utilization fidelity (average # of exercises completed per NMT session), utilization frequency (average # of NMT sessions completed per week) were calculated and further evaluated for optimal adherence (≥80%, ≥10.4 exercises/session and ≥2 sessions/week, respectively) per coach. Additionally, exercise fidelity (proportion of players performing individual exercises correctly) was assessed. Coach (n = 31; 27-59 years) median cumulative utilization was 80%, utilization fidelity was 12 (of a possible 13 exercises per session) and utilization frequency was 2.3 sessions per week. Optimal adherence ranged from 52% to 71% across measures of adherence. Player exercise fidelity was 48%. Time constraint (47%) was the most frequently reported adherence barrier. While coach adherence to the NMT warm-up program was reasonably high across measures of adherence, a considerable proportion of coaches did not attain optimal adherence levels and player exercise fidelity was low.

Validation of a commercially available inertial measurement unit for recording jump load in youth basketball players.

A high incidence of overuse knee injuries among youth basketball players may be attributed to number of jumps. Wearable technology may be an effective tool for measuring jump load compared to traditional counting methods. The purpose of this study was to validate a commercially available jump counter (VERT® Classic) in youth basketball practices and games, and to identify the characteristics (i.e., height, direction, takeoff) of jumps recorded by the VERT® Classic. 46 (19F, 27M) youth basketball players wore a VERT® Classic and were recorded on video during games and practices. The number of jumps recorded by the VERT® Classic and evaluated by video raters were compared for each jump characteristic using intraclass correlation coefficient (ICC(3,k)), mean offset, and limits of agreement. The number and percent of VERT® Classic jumps and corresponding video jumps according to timestamp were reported. VERT® Classic jumps had excellent reliability with video-counted jumps over 15 cm (ICC(3,k) = 0.958), with a mean offset of -2.4 jumps (fewer VERT® Classic) and limits of agreement -12.6 to 7.8 jumps. Pairs of corresponding jumps represented 68.0% of total video jumps and 92.0% of VERT® Classic jumps. The VERT® Classic can provide an estimate of jump load in youth basketball.

Overuse injuries are prevalent in children's competitive football: a prospective study using the OSTRC Overuse Injury Questionnaire.

OBJECTIVES: To investigate the prevalence and burden of overuse injuries in children's football as well as player characteristics and their association with overuse injury risk. METHODS: This investigation is based on the control arm (10 clubs) of a randomised controlled trial investigating prevention of injuries in youth football. We conducted a prospective 20-week follow-up study on overuse injuries among Finnish football players (n=733, aged 9-14 years). Each week, we sent a text message to players' parents to ask if the player had sustained any injury during the past week. Players with overuse problem were interviewed over the phone using an overuse injury questionnaire. The main outcome measures were prevalence of all overuse injuries and substantial overuse injuries (those leading to moderate or severe reductions in participation or performance) and injury severity. RESULTS: The average response rate was 95%. In total, 343 players (46.8%) reported an overuse problem while in the study. The average weekly prevalence of all overuse problems and substantial overuse problems was 12.8% and 6.0%, respectively. Injuries affecting the knee had the highest weekly prevalence (5.7% and 2.4% for all and substantial knee problems, respectively). Girls had a higher likelihood of knee problems (OR 2.70; 95% CI 1.69 to 4.17), whereas boys had a higher likelihood of heel problems (OR 2.82; 95% CI 1.07 to 7.44). The likelihood of reporting an overuse problem increased with age (OR 1.21; 95% CI 1.00 to 1.47). CONCLUSION: Overuse injuries are prevalent in children's competitive football. Knee overuse injuries represent the greatest burden on participation and performance. TRIAL REGISTRATION NUMBER: ISRCTN14046021.

Prevalence of adolescent physical activity-related injuries in sports, leisure time, and school: the National Physical Activity Behaviour Study for children and Adolescents.

BACKGROUND: The purpose of this study was to investigate the prevalence of adolescent physical activity-related injuries in sports club activities, leisure time physical activity and school-based physical activity. The secondary aim was to investigate the differences in the prevalence of physical activity -related injuries between years 2014 and 2016. In addition, we set out to study the associations between age, sex and the frequency of physical activity and injury prevalence. METHODS: This cross-sectional study is based on the National Physical Activity Behaviour Study for Children and Adolescents (LIITU in Finnish) conducted in years 2014 and 2016. The subjects completed an online questionnaire in the classroom during school hours. A total of 8406 subjects participated in the current study. Out of these, 49% were boys and 51% were girls. The proportions of 11-, 13-, and 15-year-olds were 35%, 34% and 31%, respectively. RESULTS: In the combined data for 2014 and 2016, injury prevalence was higher in sports club activities (46%, 95% CI 44.8-47.8) than in leisure time PA (30%, 95% CI, 28.5-30.5) or school-based PA (18%, 95% CI, 17.4-19.1). In leisure time PA, the injury prevalence was higher than in school-based PA. In all the three settings, injury prevalence was higher in 2016 than in 2014. Frequency of PA was associated with a higher risk for PA-related injuries in sports clubs and leisure time. CONCLUSIONS: With half of the subjects reporting at least one PA-related injury during the past year, results indicate that adolescent PA-related injuries are a large-scale problem. There is a worrisome rise in injury prevalence in recent years. From a public health standpoint, there is an urgent need to invest in injury prevention to reverse this trend.

No association between static and dynamic postural control and ACL injury risk among female elite handball and football players: a prospective study of 838 players.

BACKGROUND: Research on balance measures as potential risk factors for ACL injury is limited. OBJECTIVE: To assess whether postural control was associated with an increased risk for ACL injuries in female elite handball and football players. METHOD: Premier league players were tested in the preseason and followed prospectively for ACL injury risk from 2007 through 2015. At baseline, we recorded player demographics, playing experience, ACL and ankle injury history. We measured centre of pressure velocity in single-leg stabilisation tests and reach distances in the Star Excursion Balance Test. To examine the stability of postural control measures over time, we examined their short-term and long-term reproducibility. We generated logistic regression models, 1 for each of the proposed risk factors. RESULTS: A total of 55 (6.6%) out of 838 players (age 21±4 years; height 170±6 cm; body mass 66±8 kg) sustained a non-contact ACL injury after baseline testing (1.8±1.8 years). When comparing normalised balance measures between injured and uninjured players in univariate analyses, none of the variables were statistically associated with ACL injury risk. Short-term and long-term reproducibility of the selected variables was poor. Players with a previous ACL injury had a 3-fold higher risk of sustaining a new ACL injury compared with previously uninjured players (OR 2.9, CI 1.4 to 5.7). CONCLUSIONS: None of postural control measures examined were associated with increased ACL injury risk among female elite handball and football players. Hence, as measured in the current investigation, the variables included cannot be used to predict ACL injury risk.

Epidemiology of Overuse Injuries in Youth Team Sports: A 3-year Prospective Study.

Prospective studies on overuse injuries and their impact on athletic training among youth team sports are scarce. The purpose of this study was to investigate the incidence, severity and player related risk factors of overuse injuries among young (12-20 years) basketball and floorball players. A total of 387 players participated in a 3-year prospective study. Each player completed a baseline questionnaire regarding their background information. Overuse injuries that prevented players to fully or partly participate in their regular training were collected. In all, 204 overuse injuries were registered (injury incidence 1.51 injuries/1 000 h of exposure; 95% CI 1.35-1.78). Most of the injuries involved the knee (35%) and lower back (21%), and were classified as severe (44%). Injury incidence was 1.51 (95% CI 1.2-1.82) and 1.61 (95% CI 1.32-1.91) in basketball and floorball, respectively. Incidence was significantly higher among female compared with male players (incidence rate ratio 1.58; 95% CI 1.20-2.09). Previous injury and playing at adult level were the strongest factors associated with occurrence of an overuse injury. In conclusion, overuse injuries of the knee and low back are relatively common in youth basketball and floorball. Effective prevention strategies as well as training load monitoring is needed in youth team sports.

Single-Leg Squat as a Tool to Evaluate Young Athletes' Frontal Plane Knee Control.

OBJECTIVE: To determine the agreement between 2-dimensional video analysis and subjective visual assessment by a physiotherapist in evaluating young athletes' knee control, and to determine the intrarater reliability and inter-rater reliability of the single-leg squat test. DESIGN: Frontal plane knee control was assessed by a physiotherapist on a 3-point scale. Frontal plane projection angles were calculated from video images. To determine the intrarater reliability, a physiotherapist reassessed 60 subjects' performances from a video. For the inter-rater reliability, 20 subjects were assessed by both the physiotherapist and a nonexperienced tester. The study continued for 3 test years. SETTING: Research institute. PARTICIPANTS: Three hundred and seventy-eight floorball, basketball, ice hockey, and volleyball players. ASSESSMENT OF VARIABLES: Knee control was assessed to be good, reduced, or poor. MAIN OUTCOME MEASURES: Agreement between the video analysis and subjectively assessed frontal plane knee control. Intrarater reliability and inter-rater reliability. RESULTS: There were statistically significant differences in the mean frontal plane knee angles between subjects rated as having "good," "reduced," or "poor" knee control. Intrarater reliability was fair for the assessments in the first year, moderate (dominant leg) and good (nondominant leg) for the second year, and very good (dominant leg) and good (nondominant leg) for the third year. Inter-rater reliability was fair/poor. CONCLUSIONS: This study suggests that by using the subjective assessment of the single-leg squat task, it is possible to detect differences in frontal plane knee control in young team sport athletes. The assessment can be considered to be reliable for clinical use when performed by an experienced tester.

Low Back Pain in Young Basketball and Floorball Players.

OBJECTIVE: The aim of the study was to investigate the prevalence and risk factors of low back pain (LBP) in young female and male basketball and floorball players. DESIGN: Cross-sectional study. SETTING: Nine basketball teams and 9 floorball teams from Tampere city district, Finland. PARTICIPANTS: Four hundred one young female and male players (mean age: 15.8 ± 1.9 years). ASSESSMENT OF RISK FACTORS: Age, gender, sport, and family history of musculoskeletal disorders were assessed as risk factors for LBP. Adjustment was made on team level to avoid random effects associated with a team. MAIN OUTCOME MEASURES: Information of players' background factors and LBP episodes was collected by a structured questionnaire. RESULTS: Forty-four percentage of the basketball players and 62% of floorball players had suffered from LBP during the previous 12 months. Prevalence of LBP during the previous year was significantly higher among floorball players (P = 0.001). In both sports, prevalence of pain symptoms was the highest during the competitive playing season. Family history of musculoskeletal disorders [OR (odds ratio), 2.02, 95% confidence interval (CI), 1.22-3.34] and higher age (OR, 1.22, 95% CI, 1.05-1.41) were associated with LBP in players. CONCLUSIONS: The study attested that LBP is a relatively common complaint in young team sport players. Targeted measures to examine causes, risk factors, and prevention of LBP in youth sports are needed.